Use of acetalized vinyl alcohol polymers as thickeners

Abstract

The invention relates to the use of acetalized vinyl alcohol polymers with a molecular weight Mw greater than 100 000 as thickeners, the thickeners being obtained by acetalizing partially or fully hydrolyzed vinyl acetate homopolymers, or partially or fully hydrolyzed vinyl acetate copolymers which, besides vinyl acetate units, also contain comonomer units which derive from one or more comonomers selected from the group consisting of 1 -(C 1-5 ) alkylvinyl esters of C 1-5 carboxylic acids, allyl esters, vinyl esters of alpha-branched C 1-12 carboxylic acids, and C 1-8 -alkyl (meth)acrylates.

What is claimed is:  
     
         1 . A process for thickening a liquid composition, said process comprising adding to said liquid composition or to a mixture used to prepare said liquid composition, an effective thickening amount of a thickener comprising an acetalized vinyl alcohol polymer with a molecular weight Mw greater than 100,000, said acetalized vinyl alcohol polymer comprising at least one of an acetalized partially or fully hydrolyzed vinyl acetate homopolymer, or an acetalized partially or fully hydrolyzed vinyl acetate copolymer which besides vinyl acetate units also contains comonomer units derived from one or more comonomers from the group of 1-(C 1-5 )alkylvinyl esters of C 1-5  carboxylic acids, allyl esters, vinyl esters of alpha-branched C 5-12  carboxylic acids, and C 1-18 -alkyl (meth)acrylates.  
     
     
         2 . The process of  claim 1 , wherein said partially or fully hydrolyzed vinyl acetate homo- or copolymers have a degree of hydrolysis of from 75 to 100 mol %, and have been acetalized with aliphatic or aromatic aldehydes to a degree of acetalization of from 0.5 to 100 mol %.  
     
     
         3 . The process of  claim 2 , wherein the aliphatic or aromatic aldehydes are substituted by one or more substituents selected from hydroxyl, carboxyl, sulfonate, ammonium, and aldehyde radicals.  
     
     
         4 . The process of  claim 1 , wherein the partially or fully hydrolyzed vinyl acetate homo- or copolymers have been acetalized with one or more aldehydes selected from formaldehyde, acetaldehyde, benzaldehyde, glyoxylic acid, and glyceraldehyde.  
     
     
         5 . The process of  claim 1 , wherein the partially or fully hydrolyzed vinyl acetate copolymers contain, besides vinyl acetate units, comonomer units of one or more comonomers selected from isopropenyl acetate, vinyl esters of alpha-branched C 9-11  carboxylic acids, and C 1-10 -alkyl (meth)acrylates.  
     
     
         6 . The process of  claim 6 , wherein the thickeners are obtained by acetalization of partially or fully hydrolyzed vinyl acetate copolymers containing moieties derived from comonomers selected from copolymers having from 0.3 to 15% by weight of any of isopropenyl acetate, vinyl esters of alpha-branched C 9-11  carboxylic acids, and C 1-10  alkylmethacrylates.  
     
     
         7 . The process of  claim 5 , wherein the proportion of each comonomer unit other than vinyl acetate is from 0.3 to 15% by weight, based on the total weight of the partially or fully hydrolyzed vinyl acetate copolymer.  
     
     
         8 . The process of  claim 6 , wherein the thickeners are obtained by acetalization of partially or fully hydrolyzed vinyl acetate copolymers selected from: 
 copolymers having from 0.3 to 15% by weight of any of isopropenyl acetate, vinyl esters of alpha-branched C 9-11  carboxylic acids, methyl, ethyl, butyl or 2-ethylhexyl acrylate(s) or 2-ethylhexyl methacrylate;    copolymers having from 0.3 to 15% by weight of isopropenyl acetate units and from 0.3 to 15% by weight of vinyl esters of alpha-branched C 9-11  carboxylic acids;    copolymers having from 0.5 to 6% by weight of isopropenyl acetate, from 0.5 to 6% by weight of vinyl esters of alpha-branched C 10  carboxylic acids, and from 0.5 to 6% by weight of methyl acrylate; and    copolymers having from 0.5 to 6% by weight of isopropenyl acetate, from 0.5 to 6% by weight of 2-ethylhexyl methacrylate, and from 0.5 to 6% by weight of methyl acrylate.    
     
     
         9 . The process of  claim 1 , wherein the thickeners are in aqueous solution, in powder form, as an additive in aqueous polymer dispersions or in redispersible polymer powders, in amounts of from 0.01 to 20% by weight of thickener (as solid), based on the total weight of the composition to be thickened, wherein the composition to be thickened is selected from cosmetic compositions, pharmaceutical compositions, water-based silicone emulsions, silicone oils, coating compositions, adhesive compositions, or construction compositions.  
     
     
         10 . The process of  claim 9 , wherein said construction composition is a hydraulically setting or non-hydraulically setting composition.  
     
     
         11 . The process of  claim 10 , wherein said construction composition comprises a cement-based construction adhesive, a cement-based dry mortar, a cement-based flowable composition, a cement-based render, or a cement-based exterior insulation system adhesive, or a cement-based non-shrink grout.  
     
     
         12 . The process of  claim 10 , wherein said construction composition comprises a gypsum-containing composition.  
     
     
         13 . The process of  claim 10 , wherein said gypsum-containing composition is a render or a troweling composition.  
     
     
         14 . The process of  claim 10 , wherein said composition comprises a cement-free troweling composition, a render, a tile adhesive, or an exterior insulation system adhesive.  
     
     
         15 . The process of  claim 10 , wherein said construction composition further comprises at least one water-redispersible polymer powder.  
     
     
         16 . A hydraulically setting or non-hydraulically setting composition thickened by the process of  claim 1 .  
     
     
         17 . A hydraulically settable or non-hydraulically settable composition, comprising an effective, thickening amount of a thickener component comprising an acetalized vinyl alcohol polymer with a molecular weight Mw greater than 100,000 prepared by acetalizing partially or fully hydrolyzed vinyl acetate homopolymer, or by acetalizing a partially or fully hydrolyzed vinyl acetate copolymer which besides vinyl acetate units also contains comonomer units derived from one or more comonomers from the group of 1-(C 1-5 )alkylvinyl esters of C 1-5  carboxylic acids, allyl esters, vinyl esters of alpha-branched C 5-12  carboxylic acids, and C 1-18 -alkyl (meth)acrylates.  
     
     
         18 . The composition of  claim 17  which is a cement-based composition.  
     
     
         19 . The composition of  claim 17 , which is a concrete, a cement mortar, a lime mortar, or a gypsum mortar.  
     
     
         20 . The composition of  claim 17  which is a tile adhesive, a render, or an exterior insulation system adhesive.  
     
     
         21 . The composition of  claim 17 , wherein said thickener component comprises from 0.1 to 20 weight percent of the total composition, based on solids.  
     
     
         22 . The composition of  claim 21  wherein said composition is a cement-type composition containing from 0.1 to 5 weight percent of said thickener component.